Container stopper



y 1932- J. A. KEENAN CONTAINER STOPPER Filed Sept. 26. 1930 Bill/6722507Jfl. K'e em Patented July 5, 1932 PATENT OFFICE JOHN A. KEENAN, OFMADISON,

WISCONSIN, ASSIGNOR TO GENERAL LABORATORIES,

' INC OF MADISON, WISCONSIN, A CORPORATION OF DELAWARE CONTAINER STOPPERApplication filed September 26, 1930. Serial No. 484,488.

This invention relates to caps for bottles or similar containers.

Generally stated, the object of the invention is to provide a novel andimproved construction whereby a screw-threaded cap of this kind, or acap otherwise formed to enclose the neck of a bottle or similarcontainer, is provided with an automatic vent or release valve in theform of an elastic diaphragm having a puncture at its middle, and havingits outer edges formed to bear upon the neck of the bottle or othercontainer, under the pressure of a cap, and to thus provide a tightjoint, thereby preventing escape of gas from the bottle or containereverywhere except through said puncture.

. To these and other useful ends the invention consists in mattershereinafter set forth and claimed and shown in the accompanying drawingin which- Fig. 1 is a top view or plan of a bottle cap embodying theprinciples of the invention.

Fig. 2 is a vertical section on line 22 in Fig. 1.

Fig. 3 is a similar view, but showing a diaphragm outwardly bulged toautomatically vent any accumulated gas pressure in the bottle or othercontainer.-

\ As thus illustrated, the invention comprises a cap having side walls 1and a top Wall 2 the inner surface of the side walls, which arepreferably cylindrical, being provided with screw threads 3 to engagethe screw threads 4 on the neck of the bottle 5 or other container. Thecap can be of bakelite or metal or other material.

An elastic diaphragm 6, of dished form, is placed on the top of thebottle neck, as shown, within the cap, and may be fastened to the cap,or may be left loose so that a new diaphragm can be supplied whennecessary to take the place of one that has been worn out. Thisdiaphragm preferably has a puncture 7 at its middle. When the cap isscrewed down in place, the edge portions of the diaphragm arecompressed, as shown, upon the top of the bottle neck, by the overlyingtop wall of the cap, thus providing a tight joint which will prevent theescape of accumulated gas pressure except through the said puncture.When pressure accumulates in the bottle or other container, thediaphragm will bulge outwardly through the opening 8 at the top of thecap, as shown in Fig. 3 of the drawing. l

, Preferably, the top portion of the cap is polygonal, having flat edges9 as shown in Fig. 1 of the drawing, with notches 10 at the cornersbetween said flat or straight edges. This gives the hand a better gripon the cap, and should occasion require, a wrench could be applied tothe cap to screw it in place, or to remove it from the bottle neck.

With a cap of this kind, a leak-proof closure is provided for a'bottleor other container, for as soon as any accumulated pressure has beensufliciently vented or discharged through the puncture 7, this puncturewill then automatically close, and seal the bottle.

It will be understood, of course, that the diaphragm 6 may be of rubber,or other elastic material, and that the opening 8 is preferably ofsuflicient area to permit the middle portion of the diaphragm to bulgeoutwardly in a manner to open the puncture 7 and thereby vent theaccumulated gas pressure to the atmosphere.

What I claim as my invention is:

1. A cap for bottles or similar containers, said cap havin a top wallprovided with an opening, and having side walls internally formed toengage holding means on the neck of the bottle or other container,together with a flat elastic diaphragm having its marginal portionsclamped upon the upper edge of the neck of the bottle or other containerby the downward pressure of the top wall of the cap, with the diaphragmlying flat against the underside of said cap, sealing the bottle againstescape of fluid pressure between the cap and bottle, the middle ortionof the diaphragm being provided I with a normally closed puncture toautomatically vent any accumulated pressure in the bottle or othercontainer through said opening in the top of the cap, said opening beingformed to cause said diaphragm to balloon outward through said openingto open said puncture to relieve internal fluid pressure.

2. A structure as specified in claim 1, said cap being of hard andunyielding material, and said holding means comprising screw threads,direction will compress the edge portions of said fiat diaphragm twothicknesses less than the middle portion of the diaphragm, forming aleak-proof closure for the bottle or other container, while rotation ofthe cap in the opposite direction will remove the cap from the containerneck.

3. A structure as specified in claim 1, said opening in the top of thecap being round and central and of sufficient size to cause thediaphragm to bulge therein under pressure in the container, thereby toopen said puncture and vent the accumulated gas pressure to theatmosphere.

Specification signed this 23rd day of September, 1930.

JOHN A. KEENAN.

whereby rotation of the cap in one

